Help with google dance explanation?

So I have been back linking and optimising my site for a while now and was up to around 200-300 organic searches a day but the past 2 days it has dramatically dropped to 50-100 and I see some keywords I was ranking for have now dropped either loads or off google is this normal I heard someone say it may be a google dance but I am not sure what this is.

Note that adblockers might block our captcha, and other functionality on BHW so if you don't see the captcha or see reduced functionality please disable adblockers to ensure full functionality, note we only allow relevant management verified ads on BHW.